Adverse influence of diazepam upon resistance to Klebsiella pneumoniae infection in mice

Male and female mice, IOPS OF1 strain, received an i.p. injection of diazepam 1,2,4 or 8 mg/kg daily for 3 days prior to i.p. challenge with Klebsiella pneumoniae. Diazepam pretreatment increased mortality due to Klebsiella pneumoniae indicating that diazepam alters natural resistance to infection. The mechanism has not been elucidated but would appear to involve T cells and/or macrophages.